1/* 2 * Monkey's Audio lossless audio decoder 3 * Copyright (c) 2007 Benjamin Zores <ben@geexbox.org> 4 * based upon libdemac from Dave Chapman. 5 * 6 * This file is part of FFmpeg. 7 * 8 * FFmpeg is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; either 11 * version 2.1 of the License, or (at your option) any later version. 12 * 13 * FFmpeg is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with FFmpeg; if not, write to the Free Software 20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 21 */ 22 23#define ALT_BITSTREAM_READER_LE 24#include "avcodec.h" 25#include "dsputil.h" 26#include "get_bits.h" 27#include "bytestream.h" 28 29/** 30 * @file 31 * Monkey's Audio lossless audio decoder 32 */ 33 34#define BLOCKS_PER_LOOP 4608 35#define MAX_CHANNELS 2 36#define MAX_BYTESPERSAMPLE 3 37 38#define APE_FRAMECODE_MONO_SILENCE 1 39#define APE_FRAMECODE_STEREO_SILENCE 3 40#define APE_FRAMECODE_PSEUDO_STEREO 4 41 42#define HISTORY_SIZE 512 43#define PREDICTOR_ORDER 8 44/** Total size of all predictor histories */ 45#define PREDICTOR_SIZE 50 46 47#define YDELAYA (18 + PREDICTOR_ORDER*4) 48#define YDELAYB (18 + PREDICTOR_ORDER*3) 49#define XDELAYA (18 + PREDICTOR_ORDER*2) 50#define XDELAYB (18 + PREDICTOR_ORDER) 51 52#define YADAPTCOEFFSA 18 53#define XADAPTCOEFFSA 14 54#define YADAPTCOEFFSB 10 55#define XADAPTCOEFFSB 5 56 57/** 58 * Possible compression levels 59 * @{ 60 */ 61enum APECompressionLevel { 62 COMPRESSION_LEVEL_FAST = 1000, 63 COMPRESSION_LEVEL_NORMAL = 2000, 64 COMPRESSION_LEVEL_HIGH = 3000, 65 COMPRESSION_LEVEL_EXTRA_HIGH = 4000, 66 COMPRESSION_LEVEL_INSANE = 5000 67}; 68/** @} */ 69 70#define APE_FILTER_LEVELS 3 71 72/** Filter orders depending on compression level */ 73static const uint16_t ape_filter_orders[5][APE_FILTER_LEVELS] = { 74 { 0, 0, 0 }, 75 { 16, 0, 0 }, 76 { 64, 0, 0 }, 77 { 32, 256, 0 }, 78 { 16, 256, 1280 } 79}; 80 81/** Filter fraction bits depending on compression level */ 82static const uint8_t ape_filter_fracbits[5][APE_FILTER_LEVELS] = { 83 { 0, 0, 0 }, 84 { 11, 0, 0 }, 85 { 11, 0, 0 }, 86 { 10, 13, 0 }, 87 { 11, 13, 15 } 88}; 89 90 91/** Filters applied to the decoded data */ 92typedef struct APEFilter { 93 int16_t *coeffs; ///< actual coefficients used in filtering 94 int16_t *adaptcoeffs; ///< adaptive filter coefficients used for correcting of actual filter coefficients 95 int16_t *historybuffer; ///< filter memory 96 int16_t *delay; ///< filtered values 97 98 int avg; 99} APEFilter; 100 101typedef struct APERice { 102 uint32_t k; 103 uint32_t ksum; 104} APERice; 105 106typedef struct APERangecoder { 107 uint32_t low; ///< low end of interval 108 uint32_t range; ///< length of interval 109 uint32_t help; ///< bytes_to_follow resp. intermediate value 110 unsigned int buffer; ///< buffer for input/output 111} APERangecoder; 112 113/** Filter histories */ 114typedef struct APEPredictor { 115 int32_t *buf; 116 117 int32_t lastA[2]; 118 119 int32_t filterA[2]; 120 int32_t filterB[2]; 121 122 int32_t coeffsA[2][4]; ///< adaption coefficients 123 int32_t coeffsB[2][5]; ///< adaption coefficients 124 int32_t historybuffer[HISTORY_SIZE + PREDICTOR_SIZE]; 125} APEPredictor; 126 127/** Decoder context */ 128typedef struct APEContext { 129 AVCodecContext *avctx; 130 DSPContext dsp; 131 int channels; 132 int samples; ///< samples left to decode in current frame 133 134 int fileversion; ///< codec version, very important in decoding process 135 int compression_level; ///< compression levels 136 int fset; ///< which filter set to use (calculated from compression level) 137 int flags; ///< global decoder flags 138 139 uint32_t CRC; ///< frame CRC 140 int frameflags; ///< frame flags 141 int currentframeblocks; ///< samples (per channel) in current frame 142 int blocksdecoded; ///< count of decoded samples in current frame 143 APEPredictor predictor; ///< predictor used for final reconstruction 144 145 int32_t decoded0[BLOCKS_PER_LOOP]; ///< decoded data for the first channel 146 int32_t decoded1[BLOCKS_PER_LOOP]; ///< decoded data for the second channel 147 148 int16_t* filterbuf[APE_FILTER_LEVELS]; ///< filter memory 149 150 APERangecoder rc; ///< rangecoder used to decode actual values 151 APERice riceX; ///< rice code parameters for the second channel 152 APERice riceY; ///< rice code parameters for the first channel 153 APEFilter filters[APE_FILTER_LEVELS][2]; ///< filters used for reconstruction 154 155 uint8_t *data; ///< current frame data 156 uint8_t *data_end; ///< frame data end 157 const uint8_t *ptr; ///< current position in frame data 158 const uint8_t *last_ptr; ///< position where last 4608-sample block ended 159 160 int error; 161} APEContext; 162 163// TODO: dsputilize 164 165static av_cold int ape_decode_init(AVCodecContext * avctx) 166{ 167 APEContext *s = avctx->priv_data; 168 int i; 169 170 if (avctx->extradata_size != 6) { 171 av_log(avctx, AV_LOG_ERROR, "Incorrect extradata\n"); 172 return -1; 173 } 174 if (avctx->bits_per_coded_sample != 16) { 175 av_log(avctx, AV_LOG_ERROR, "Only 16-bit samples are supported\n"); 176 return -1; 177 } 178 if (avctx->channels > 2) { 179 av_log(avctx, AV_LOG_ERROR, "Only mono and stereo is supported\n"); 180 return -1; 181 } 182 s->avctx = avctx; 183 s->channels = avctx->channels; 184 s->fileversion = AV_RL16(avctx->extradata); 185 s->compression_level = AV_RL16(avctx->extradata + 2); 186 s->flags = AV_RL16(avctx->extradata + 4); 187 188 av_log(avctx, AV_LOG_DEBUG, "Compression Level: %d - Flags: %d\n", s->compression_level, s->flags); 189 if (s->compression_level % 1000 || s->compression_level > COMPRESSION_LEVEL_INSANE) { 190 av_log(avctx, AV_LOG_ERROR, "Incorrect compression level %d\n", s->compression_level); 191 return -1; 192 } 193 s->fset = s->compression_level / 1000 - 1; 194 for (i = 0; i < APE_FILTER_LEVELS; i++) { 195 if (!ape_filter_orders[s->fset][i]) 196 break; 197 s->filterbuf[i] = av_malloc((ape_filter_orders[s->fset][i] * 3 + HISTORY_SIZE) * 4); 198 } 199 200 dsputil_init(&s->dsp, avctx); 201 avctx->sample_fmt = SAMPLE_FMT_S16; 202 avctx->channel_layout = (avctx->channels==2) ? CH_LAYOUT_STEREO : CH_LAYOUT_MONO; 203 return 0; 204} 205 206static av_cold int ape_decode_close(AVCodecContext * avctx) 207{ 208 APEContext *s = avctx->priv_data; 209 int i; 210 211 for (i = 0; i < APE_FILTER_LEVELS; i++) 212 av_freep(&s->filterbuf[i]); 213 214 av_freep(&s->data); 215 return 0; 216} 217 218/** 219 * @defgroup rangecoder APE range decoder 220 * @{ 221 */ 222 223#define CODE_BITS 32 224#define TOP_VALUE ((unsigned int)1 << (CODE_BITS-1)) 225#define SHIFT_BITS (CODE_BITS - 9) 226#define EXTRA_BITS ((CODE_BITS-2) % 8 + 1) 227#define BOTTOM_VALUE (TOP_VALUE >> 8) 228 229/** Start the decoder */ 230static inline void range_start_decoding(APEContext * ctx) 231{ 232 ctx->rc.buffer = bytestream_get_byte(&ctx->ptr); 233 ctx->rc.low = ctx->rc.buffer >> (8 - EXTRA_BITS); 234 ctx->rc.range = (uint32_t) 1 << EXTRA_BITS; 235} 236 237/** Perform normalization */ 238static inline void range_dec_normalize(APEContext * ctx) 239{ 240 while (ctx->rc.range <= BOTTOM_VALUE) { 241 ctx->rc.buffer <<= 8; 242 if(ctx->ptr < ctx->data_end) 243 ctx->rc.buffer += *ctx->ptr; 244 ctx->ptr++; 245 ctx->rc.low = (ctx->rc.low << 8) | ((ctx->rc.buffer >> 1) & 0xFF); 246 ctx->rc.range <<= 8; 247 } 248} 249 250/** 251 * Calculate culmulative frequency for next symbol. Does NO update! 252 * @param ctx decoder context 253 * @param tot_f is the total frequency or (code_value)1<<shift 254 * @return the culmulative frequency 255 */ 256static inline int range_decode_culfreq(APEContext * ctx, int tot_f) 257{ 258 range_dec_normalize(ctx); 259 ctx->rc.help = ctx->rc.range / tot_f; 260 return ctx->rc.low / ctx->rc.help; 261} 262 263/** 264 * Decode value with given size in bits 265 * @param ctx decoder context 266 * @param shift number of bits to decode 267 */ 268static inline int range_decode_culshift(APEContext * ctx, int shift) 269{ 270 range_dec_normalize(ctx); 271 ctx->rc.help = ctx->rc.range >> shift; 272 return ctx->rc.low / ctx->rc.help; 273} 274 275 276/** 277 * Update decoding state 278 * @param ctx decoder context 279 * @param sy_f the interval length (frequency of the symbol) 280 * @param lt_f the lower end (frequency sum of < symbols) 281 */ 282static inline void range_decode_update(APEContext * ctx, int sy_f, int lt_f) 283{ 284 ctx->rc.low -= ctx->rc.help * lt_f; 285 ctx->rc.range = ctx->rc.help * sy_f; 286} 287 288/** Decode n bits (n <= 16) without modelling */ 289static inline int range_decode_bits(APEContext * ctx, int n) 290{ 291 int sym = range_decode_culshift(ctx, n); 292 range_decode_update(ctx, 1, sym); 293 return sym; 294} 295 296 297#define MODEL_ELEMENTS 64 298 299/** 300 * Fixed probabilities for symbols in Monkey Audio version 3.97 301 */ 302static const uint16_t counts_3970[22] = { 303 0, 14824, 28224, 39348, 47855, 53994, 58171, 60926, 304 62682, 63786, 64463, 64878, 65126, 65276, 65365, 65419, 305 65450, 65469, 65480, 65487, 65491, 65493, 306}; 307 308/** 309 * Probability ranges for symbols in Monkey Audio version 3.97 310 */ 311static const uint16_t counts_diff_3970[21] = { 312 14824, 13400, 11124, 8507, 6139, 4177, 2755, 1756, 313 1104, 677, 415, 248, 150, 89, 54, 31, 314 19, 11, 7, 4, 2, 315}; 316 317/** 318 * Fixed probabilities for symbols in Monkey Audio version 3.98 319 */ 320static const uint16_t counts_3980[22] = { 321 0, 19578, 36160, 48417, 56323, 60899, 63265, 64435, 322 64971, 65232, 65351, 65416, 65447, 65466, 65476, 65482, 323 65485, 65488, 65490, 65491, 65492, 65493, 324}; 325 326/** 327 * Probability ranges for symbols in Monkey Audio version 3.98 328 */ 329static const uint16_t counts_diff_3980[21] = { 330 19578, 16582, 12257, 7906, 4576, 2366, 1170, 536, 331 261, 119, 65, 31, 19, 10, 6, 3, 332 3, 2, 1, 1, 1, 333}; 334 335/** 336 * Decode symbol 337 * @param ctx decoder context 338 * @param counts probability range start position 339 * @param counts_diff probability range widths 340 */ 341static inline int range_get_symbol(APEContext * ctx, 342 const uint16_t counts[], 343 const uint16_t counts_diff[]) 344{ 345 int symbol, cf; 346 347 cf = range_decode_culshift(ctx, 16); 348 349 if(cf > 65492){ 350 symbol= cf - 65535 + 63; 351 range_decode_update(ctx, 1, cf); 352 if(cf > 65535) 353 ctx->error=1; 354 return symbol; 355 } 356 /* figure out the symbol inefficiently; a binary search would be much better */ 357 for (symbol = 0; counts[symbol + 1] <= cf; symbol++); 358 359 range_decode_update(ctx, counts_diff[symbol], counts[symbol]); 360 361 return symbol; 362} 363/** @} */ // group rangecoder 364 365static inline void update_rice(APERice *rice, int x) 366{ 367 int lim = rice->k ? (1 << (rice->k + 4)) : 0; 368 rice->ksum += ((x + 1) / 2) - ((rice->ksum + 16) >> 5); 369 370 if (rice->ksum < lim) 371 rice->k--; 372 else if (rice->ksum >= (1 << (rice->k + 5))) 373 rice->k++; 374} 375 376static inline int ape_decode_value(APEContext * ctx, APERice *rice) 377{ 378 int x, overflow; 379 380 if (ctx->fileversion < 3990) { 381 int tmpk; 382 383 overflow = range_get_symbol(ctx, counts_3970, counts_diff_3970); 384 385 if (overflow == (MODEL_ELEMENTS - 1)) { 386 tmpk = range_decode_bits(ctx, 5); 387 overflow = 0; 388 } else 389 tmpk = (rice->k < 1) ? 0 : rice->k - 1; 390 391 if (tmpk <= 16) 392 x = range_decode_bits(ctx, tmpk); 393 else { 394 x = range_decode_bits(ctx, 16); 395 x |= (range_decode_bits(ctx, tmpk - 16) << 16); 396 } 397 x += overflow << tmpk; 398 } else { 399 int base, pivot; 400 401 pivot = rice->ksum >> 5; 402 if (pivot == 0) 403 pivot = 1; 404 405 overflow = range_get_symbol(ctx, counts_3980, counts_diff_3980); 406 407 if (overflow == (MODEL_ELEMENTS - 1)) { 408 overflow = range_decode_bits(ctx, 16) << 16; 409 overflow |= range_decode_bits(ctx, 16); 410 } 411 412 if (pivot < 0x10000) { 413 base = range_decode_culfreq(ctx, pivot); 414 range_decode_update(ctx, 1, base); 415 } else { 416 int base_hi = pivot, base_lo; 417 int bbits = 0; 418 419 while (base_hi & ~0xFFFF) { 420 base_hi >>= 1; 421 bbits++; 422 } 423 base_hi = range_decode_culfreq(ctx, base_hi + 1); 424 range_decode_update(ctx, 1, base_hi); 425 base_lo = range_decode_culfreq(ctx, 1 << bbits); 426 range_decode_update(ctx, 1, base_lo); 427 428 base = (base_hi << bbits) + base_lo; 429 } 430 431 x = base + overflow * pivot; 432 } 433 434 update_rice(rice, x); 435 436 /* Convert to signed */ 437 if (x & 1) 438 return (x >> 1) + 1; 439 else 440 return -(x >> 1); 441} 442 443static void entropy_decode(APEContext * ctx, int blockstodecode, int stereo) 444{ 445 int32_t *decoded0 = ctx->decoded0; 446 int32_t *decoded1 = ctx->decoded1; 447 448 ctx->blocksdecoded = blockstodecode; 449 450 if (ctx->frameflags & APE_FRAMECODE_STEREO_SILENCE) { 451 /* We are pure silence, just memset the output buffer. */ 452 memset(decoded0, 0, blockstodecode * sizeof(int32_t)); 453 memset(decoded1, 0, blockstodecode * sizeof(int32_t)); 454 } else { 455 while (blockstodecode--) { 456 *decoded0++ = ape_decode_value(ctx, &ctx->riceY); 457 if (stereo) 458 *decoded1++ = ape_decode_value(ctx, &ctx->riceX); 459 } 460 } 461 462 if (ctx->blocksdecoded == ctx->currentframeblocks) 463 range_dec_normalize(ctx); /* normalize to use up all bytes */ 464} 465 466static void init_entropy_decoder(APEContext * ctx) 467{ 468 /* Read the CRC */ 469 ctx->CRC = bytestream_get_be32(&ctx->ptr); 470 471 /* Read the frame flags if they exist */ 472 ctx->frameflags = 0; 473 if ((ctx->fileversion > 3820) && (ctx->CRC & 0x80000000)) { 474 ctx->CRC &= ~0x80000000; 475 476 ctx->frameflags = bytestream_get_be32(&ctx->ptr); 477 } 478 479 /* Keep a count of the blocks decoded in this frame */ 480 ctx->blocksdecoded = 0; 481 482 /* Initialize the rice structs */ 483 ctx->riceX.k = 10; 484 ctx->riceX.ksum = (1 << ctx->riceX.k) * 16; 485 ctx->riceY.k = 10; 486 ctx->riceY.ksum = (1 << ctx->riceY.k) * 16; 487 488 /* The first 8 bits of input are ignored. */ 489 ctx->ptr++; 490 491 range_start_decoding(ctx); 492} 493 494static const int32_t initial_coeffs[4] = { 495 360, 317, -109, 98 496}; 497 498static void init_predictor_decoder(APEContext * ctx) 499{ 500 APEPredictor *p = &ctx->predictor; 501 502 /* Zero the history buffers */ 503 memset(p->historybuffer, 0, PREDICTOR_SIZE * sizeof(int32_t)); 504 p->buf = p->historybuffer; 505 506 /* Initialize and zero the coefficients */ 507 memcpy(p->coeffsA[0], initial_coeffs, sizeof(initial_coeffs)); 508 memcpy(p->coeffsA[1], initial_coeffs, sizeof(initial_coeffs)); 509 memset(p->coeffsB, 0, sizeof(p->coeffsB)); 510 511 p->filterA[0] = p->filterA[1] = 0; 512 p->filterB[0] = p->filterB[1] = 0; 513 p->lastA[0] = p->lastA[1] = 0; 514} 515 516/** Get inverse sign of integer (-1 for positive, 1 for negative and 0 for zero) */ 517static inline int APESIGN(int32_t x) { 518 return (x < 0) - (x > 0); 519} 520 521static av_always_inline int predictor_update_filter(APEPredictor *p, const int decoded, const int filter, const int delayA, const int delayB, const int adaptA, const int adaptB) 522{ 523 int32_t predictionA, predictionB, sign; 524 525 p->buf[delayA] = p->lastA[filter]; 526 p->buf[adaptA] = APESIGN(p->buf[delayA]); 527 p->buf[delayA - 1] = p->buf[delayA] - p->buf[delayA - 1]; 528 p->buf[adaptA - 1] = APESIGN(p->buf[delayA - 1]); 529 530 predictionA = p->buf[delayA ] * p->coeffsA[filter][0] + 531 p->buf[delayA - 1] * p->coeffsA[filter][1] + 532 p->buf[delayA - 2] * p->coeffsA[filter][2] + 533 p->buf[delayA - 3] * p->coeffsA[filter][3]; 534 535 /* Apply a scaled first-order filter compression */ 536 p->buf[delayB] = p->filterA[filter ^ 1] - ((p->filterB[filter] * 31) >> 5); 537 p->buf[adaptB] = APESIGN(p->buf[delayB]); 538 p->buf[delayB - 1] = p->buf[delayB] - p->buf[delayB - 1]; 539 p->buf[adaptB - 1] = APESIGN(p->buf[delayB - 1]); 540 p->filterB[filter] = p->filterA[filter ^ 1]; 541 542 predictionB = p->buf[delayB ] * p->coeffsB[filter][0] + 543 p->buf[delayB - 1] * p->coeffsB[filter][1] + 544 p->buf[delayB - 2] * p->coeffsB[filter][2] + 545 p->buf[delayB - 3] * p->coeffsB[filter][3] + 546 p->buf[delayB - 4] * p->coeffsB[filter][4]; 547 548 p->lastA[filter] = decoded + ((predictionA + (predictionB >> 1)) >> 10); 549 p->filterA[filter] = p->lastA[filter] + ((p->filterA[filter] * 31) >> 5); 550 551 sign = APESIGN(decoded); 552 p->coeffsA[filter][0] += p->buf[adaptA ] * sign; 553 p->coeffsA[filter][1] += p->buf[adaptA - 1] * sign; 554 p->coeffsA[filter][2] += p->buf[adaptA - 2] * sign; 555 p->coeffsA[filter][3] += p->buf[adaptA - 3] * sign; 556 p->coeffsB[filter][0] += p->buf[adaptB ] * sign; 557 p->coeffsB[filter][1] += p->buf[adaptB - 1] * sign; 558 p->coeffsB[filter][2] += p->buf[adaptB - 2] * sign; 559 p->coeffsB[filter][3] += p->buf[adaptB - 3] * sign; 560 p->coeffsB[filter][4] += p->buf[adaptB - 4] * sign; 561 562 return p->filterA[filter]; 563} 564 565static void predictor_decode_stereo(APEContext * ctx, int count) 566{ 567 APEPredictor *p = &ctx->predictor; 568 int32_t *decoded0 = ctx->decoded0; 569 int32_t *decoded1 = ctx->decoded1; 570 571 while (count--) { 572 /* Predictor Y */ 573 *decoded0 = predictor_update_filter(p, *decoded0, 0, YDELAYA, YDELAYB, YADAPTCOEFFSA, YADAPTCOEFFSB); 574 decoded0++; 575 *decoded1 = predictor_update_filter(p, *decoded1, 1, XDELAYA, XDELAYB, XADAPTCOEFFSA, XADAPTCOEFFSB); 576 decoded1++; 577 578 /* Combined */ 579 p->buf++; 580 581 /* Have we filled the history buffer? */ 582 if (p->buf == p->historybuffer + HISTORY_SIZE) { 583 memmove(p->historybuffer, p->buf, PREDICTOR_SIZE * sizeof(int32_t)); 584 p->buf = p->historybuffer; 585 } 586 } 587} 588 589static void predictor_decode_mono(APEContext * ctx, int count) 590{ 591 APEPredictor *p = &ctx->predictor; 592 int32_t *decoded0 = ctx->decoded0; 593 int32_t predictionA, currentA, A, sign; 594 595 currentA = p->lastA[0]; 596 597 while (count--) { 598 A = *decoded0; 599 600 p->buf[YDELAYA] = currentA; 601 p->buf[YDELAYA - 1] = p->buf[YDELAYA] - p->buf[YDELAYA - 1]; 602 603 predictionA = p->buf[YDELAYA ] * p->coeffsA[0][0] + 604 p->buf[YDELAYA - 1] * p->coeffsA[0][1] + 605 p->buf[YDELAYA - 2] * p->coeffsA[0][2] + 606 p->buf[YDELAYA - 3] * p->coeffsA[0][3]; 607 608 currentA = A + (predictionA >> 10); 609 610 p->buf[YADAPTCOEFFSA] = APESIGN(p->buf[YDELAYA ]); 611 p->buf[YADAPTCOEFFSA - 1] = APESIGN(p->buf[YDELAYA - 1]); 612 613 sign = APESIGN(A); 614 p->coeffsA[0][0] += p->buf[YADAPTCOEFFSA ] * sign; 615 p->coeffsA[0][1] += p->buf[YADAPTCOEFFSA - 1] * sign; 616 p->coeffsA[0][2] += p->buf[YADAPTCOEFFSA - 2] * sign; 617 p->coeffsA[0][3] += p->buf[YADAPTCOEFFSA - 3] * sign; 618 619 p->buf++; 620 621 /* Have we filled the history buffer? */ 622 if (p->buf == p->historybuffer + HISTORY_SIZE) { 623 memmove(p->historybuffer, p->buf, PREDICTOR_SIZE * sizeof(int32_t)); 624 p->buf = p->historybuffer; 625 } 626 627 p->filterA[0] = currentA + ((p->filterA[0] * 31) >> 5); 628 *(decoded0++) = p->filterA[0]; 629 } 630 631 p->lastA[0] = currentA; 632} 633 634static void do_init_filter(APEFilter *f, int16_t * buf, int order) 635{ 636 f->coeffs = buf; 637 f->historybuffer = buf + order; 638 f->delay = f->historybuffer + order * 2; 639 f->adaptcoeffs = f->historybuffer + order; 640 641 memset(f->historybuffer, 0, (order * 2) * sizeof(int16_t)); 642 memset(f->coeffs, 0, order * sizeof(int16_t)); 643 f->avg = 0; 644} 645 646static void init_filter(APEContext * ctx, APEFilter *f, int16_t * buf, int order) 647{ 648 do_init_filter(&f[0], buf, order); 649 do_init_filter(&f[1], buf + order * 3 + HISTORY_SIZE, order); 650} 651 652static void do_apply_filter(APEContext * ctx, int version, APEFilter *f, int32_t *data, int count, int order, int fracbits) 653{ 654 int res; 655 int absres; 656 657 while (count--) { 658 /* round fixedpoint scalar product */ 659 res = ctx->dsp.scalarproduct_and_madd_int16(f->coeffs, f->delay - order, f->adaptcoeffs - order, order, APESIGN(*data)); 660 res = (res + (1 << (fracbits - 1))) >> fracbits; 661 res += *data; 662 *data++ = res; 663 664 /* Update the output history */ 665 *f->delay++ = av_clip_int16(res); 666 667 if (version < 3980) { 668 /* Version ??? to < 3.98 files (untested) */ 669 f->adaptcoeffs[0] = (res == 0) ? 0 : ((res >> 28) & 8) - 4; 670 f->adaptcoeffs[-4] >>= 1; 671 f->adaptcoeffs[-8] >>= 1; 672 } else { 673 /* Version 3.98 and later files */ 674 675 /* Update the adaption coefficients */ 676 absres = FFABS(res); 677 if (absres) 678 *f->adaptcoeffs = ((res & (1<<31)) - (1<<30)) >> (25 + (absres <= f->avg*3) + (absres <= f->avg*4/3)); 679 else 680 *f->adaptcoeffs = 0; 681 682 f->avg += (absres - f->avg) / 16; 683 684 f->adaptcoeffs[-1] >>= 1; 685 f->adaptcoeffs[-2] >>= 1; 686 f->adaptcoeffs[-8] >>= 1; 687 } 688 689 f->adaptcoeffs++; 690 691 /* Have we filled the history buffer? */ 692 if (f->delay == f->historybuffer + HISTORY_SIZE + (order * 2)) { 693 memmove(f->historybuffer, f->delay - (order * 2), 694 (order * 2) * sizeof(int16_t)); 695 f->delay = f->historybuffer + order * 2; 696 f->adaptcoeffs = f->historybuffer + order; 697 } 698 } 699} 700 701static void apply_filter(APEContext * ctx, APEFilter *f, 702 int32_t * data0, int32_t * data1, 703 int count, int order, int fracbits) 704{ 705 do_apply_filter(ctx, ctx->fileversion, &f[0], data0, count, order, fracbits); 706 if (data1) 707 do_apply_filter(ctx, ctx->fileversion, &f[1], data1, count, order, fracbits); 708} 709 710static void ape_apply_filters(APEContext * ctx, int32_t * decoded0, 711 int32_t * decoded1, int count) 712{ 713 int i; 714 715 for (i = 0; i < APE_FILTER_LEVELS; i++) { 716 if (!ape_filter_orders[ctx->fset][i]) 717 break; 718 apply_filter(ctx, ctx->filters[i], decoded0, decoded1, count, ape_filter_orders[ctx->fset][i], ape_filter_fracbits[ctx->fset][i]); 719 } 720} 721 722static void init_frame_decoder(APEContext * ctx) 723{ 724 int i; 725 init_entropy_decoder(ctx); 726 init_predictor_decoder(ctx); 727 728 for (i = 0; i < APE_FILTER_LEVELS; i++) { 729 if (!ape_filter_orders[ctx->fset][i]) 730 break; 731 init_filter(ctx, ctx->filters[i], ctx->filterbuf[i], ape_filter_orders[ctx->fset][i]); 732 } 733} 734 735static void ape_unpack_mono(APEContext * ctx, int count) 736{ 737 int32_t left; 738 int32_t *decoded0 = ctx->decoded0; 739 int32_t *decoded1 = ctx->decoded1; 740 741 if (ctx->frameflags & APE_FRAMECODE_STEREO_SILENCE) { 742 entropy_decode(ctx, count, 0); 743 /* We are pure silence, so we're done. */ 744 av_log(ctx->avctx, AV_LOG_DEBUG, "pure silence mono\n"); 745 return; 746 } 747 748 entropy_decode(ctx, count, 0); 749 ape_apply_filters(ctx, decoded0, NULL, count); 750 751 /* Now apply the predictor decoding */ 752 predictor_decode_mono(ctx, count); 753 754 /* Pseudo-stereo - just copy left channel to right channel */ 755 if (ctx->channels == 2) { 756 while (count--) { 757 left = *decoded0; 758 *(decoded1++) = *(decoded0++) = left; 759 } 760 } 761} 762 763static void ape_unpack_stereo(APEContext * ctx, int count) 764{ 765 int32_t left, right; 766 int32_t *decoded0 = ctx->decoded0; 767 int32_t *decoded1 = ctx->decoded1; 768 769 if (ctx->frameflags & APE_FRAMECODE_STEREO_SILENCE) { 770 /* We are pure silence, so we're done. */ 771 av_log(ctx->avctx, AV_LOG_DEBUG, "pure silence stereo\n"); 772 return; 773 } 774 775 entropy_decode(ctx, count, 1); 776 ape_apply_filters(ctx, decoded0, decoded1, count); 777 778 /* Now apply the predictor decoding */ 779 predictor_decode_stereo(ctx, count); 780 781 /* Decorrelate and scale to output depth */ 782 while (count--) { 783 left = *decoded1 - (*decoded0 / 2); 784 right = left + *decoded0; 785 786 *(decoded0++) = left; 787 *(decoded1++) = right; 788 } 789} 790 791static int ape_decode_frame(AVCodecContext * avctx, 792 void *data, int *data_size, 793 AVPacket *avpkt) 794{ 795 const uint8_t *buf = avpkt->data; 796 int buf_size = avpkt->size; 797 APEContext *s = avctx->priv_data; 798 int16_t *samples = data; 799 int nblocks; 800 int i, n; 801 int blockstodecode; 802 int bytes_used; 803 804 if (buf_size == 0 && !s->samples) { 805 *data_size = 0; 806 return 0; 807 } 808 809 /* should not happen but who knows */ 810 if (BLOCKS_PER_LOOP * 2 * avctx->channels > *data_size) { 811 av_log (avctx, AV_LOG_ERROR, "Packet size is too big to be handled in lavc! (max is %d where you have %d)\n", *data_size, s->samples * 2 * avctx->channels); 812 return -1; 813 } 814 815 if(!s->samples){ 816 s->data = av_realloc(s->data, (buf_size + 3) & ~3); 817 s->dsp.bswap_buf((uint32_t*)s->data, (const uint32_t*)buf, buf_size >> 2); 818 s->ptr = s->last_ptr = s->data; 819 s->data_end = s->data + buf_size; 820 821 nblocks = s->samples = bytestream_get_be32(&s->ptr); 822 n = bytestream_get_be32(&s->ptr); 823 if(n < 0 || n > 3){ 824 av_log(avctx, AV_LOG_ERROR, "Incorrect offset passed\n"); 825 s->data = NULL; 826 return -1; 827 } 828 s->ptr += n; 829 830 s->currentframeblocks = nblocks; 831 buf += 4; 832 if (s->samples <= 0) { 833 *data_size = 0; 834 return buf_size; 835 } 836 837 memset(s->decoded0, 0, sizeof(s->decoded0)); 838 memset(s->decoded1, 0, sizeof(s->decoded1)); 839 840 /* Initialize the frame decoder */ 841 init_frame_decoder(s); 842 } 843 844 if (!s->data) { 845 *data_size = 0; 846 return buf_size; 847 } 848 849 nblocks = s->samples; 850 blockstodecode = FFMIN(BLOCKS_PER_LOOP, nblocks); 851 852 s->error=0; 853 854 if ((s->channels == 1) || (s->frameflags & APE_FRAMECODE_PSEUDO_STEREO)) 855 ape_unpack_mono(s, blockstodecode); 856 else 857 ape_unpack_stereo(s, blockstodecode); 858 emms_c(); 859 860 if(s->error || s->ptr > s->data_end){ 861 s->samples=0; 862 av_log(avctx, AV_LOG_ERROR, "Error decoding frame\n"); 863 return -1; 864 } 865 866 for (i = 0; i < blockstodecode; i++) { 867 *samples++ = s->decoded0[i]; 868 if(s->channels == 2) 869 *samples++ = s->decoded1[i]; 870 } 871 872 s->samples -= blockstodecode; 873 874 *data_size = blockstodecode * 2 * s->channels; 875 bytes_used = s->samples ? s->ptr - s->last_ptr : buf_size; 876 s->last_ptr = s->ptr; 877 return bytes_used; 878} 879 880AVCodec ape_decoder = { 881 "ape", 882 AVMEDIA_TYPE_AUDIO, 883 CODEC_ID_APE, 884 sizeof(APEContext), 885 ape_decode_init, 886 NULL, 887 ape_decode_close, 888 ape_decode_frame, 889 .capabilities = CODEC_CAP_SUBFRAMES, 890 .long_name = NULL_IF_CONFIG_SMALL("Monkey's Audio"), 891}; 892